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Research Strategies for the U.S. Global Change Research Program (1990)

Chapter: 4 Human Sources of Global Change

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Suggested Citation:"4 Human Sources of Global Change." National Research Council. 1990. Research Strategies for the U.S. Global Change Research Program. Washington, DC: The National Academies Press. doi: 10.17226/1743.
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Suggested Citation:"4 Human Sources of Global Change." National Research Council. 1990. Research Strategies for the U.S. Global Change Research Program. Washington, DC: The National Academies Press. doi: 10.17226/1743.
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Suggested Citation:"4 Human Sources of Global Change." National Research Council. 1990. Research Strategies for the U.S. Global Change Research Program. Washington, DC: The National Academies Press. doi: 10.17226/1743.
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Suggested Citation:"4 Human Sources of Global Change." National Research Council. 1990. Research Strategies for the U.S. Global Change Research Program. Washington, DC: The National Academies Press. doi: 10.17226/1743.
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Suggested Citation:"4 Human Sources of Global Change." National Research Council. 1990. Research Strategies for the U.S. Global Change Research Program. Washington, DC: The National Academies Press. doi: 10.17226/1743.
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Suggested Citation:"4 Human Sources of Global Change." National Research Council. 1990. Research Strategies for the U.S. Global Change Research Program. Washington, DC: The National Academies Press. doi: 10.17226/1743.
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Suggested Citation:"4 Human Sources of Global Change." National Research Council. 1990. Research Strategies for the U.S. Global Change Research Program. Washington, DC: The National Academies Press. doi: 10.17226/1743.
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Suggested Citation:"4 Human Sources of Global Change." National Research Council. 1990. Research Strategies for the U.S. Global Change Research Program. Washington, DC: The National Academies Press. doi: 10.17226/1743.
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Suggested Citation:"4 Human Sources of Global Change." National Research Council. 1990. Research Strategies for the U.S. Global Change Research Program. Washington, DC: The National Academies Press. doi: 10.17226/1743.
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4 Human Sources of Global Change OVERVIEW In its 1988 report the Committee on Global Change concluded that hu- man interactions with the earth system should be a crucial component of the USGCRP. It recommended that the initial priority for research on such interactions should be to obtain a better understanding of the human sources of global change. Other interactions in particular the human consequences and management of global change were recognized as being of fundamen- tal importance. But the most immediate requirement for progress in the overall, interdisciplinary global change program was felt to be a more sys- tematic understanding of how human activities altered chemical flows, en- ergy fluxes, and physical properties central to the operation of the earth system (NRC, 1988~. This chapter formulates a research plan for achieving a better under- standing of the human sources of global change by the end of the decade This chapter was prepared for the Committee on Global Change by Robert W. Kales, Brown University, Chairman; William C. Clark, Harvard University; Vicki Norberg-Bohm, Harvard University; and B.L. Turner II, Clark University, based on the input of the working group on Human Interaction with Global Change and a larger workshop that defined the highest-priority research areas and identified specific research needs and opportunities that could be accomplished within the next 5 years (see Appendix A for workshop participants). Members of the working group were Robert W. Kates, Brown University, Chairman; William C. Clark, Harvard Univer- sity; Thomas Lee, Massachusetts Institute of Technology; V.W. Ruttan, University of Minnesota; Chauncey Starr, Electric Power Research Institute; B.L. Turner II, Clark University; and Vicki Norberg-Bohm, Harvard University. 108

HUMAN SOURCES OF GLOBAL CHANGE INDUSTRIAL MErABOUSM INTEGRATIVE MODELS I MATERIALS DRIVING FORCES: l I POPULAllON. ECONOMY, lECHNOLOGY. AND INSmUTIONS | LAND TRANSFORMATIONS ~ -~ =~ - ~ GLOBAL EARTH SYSTEM LUND COVER __ GIDBAL GREENHOUSE INFORMAllON GLOBAL CONVERSION: ENERGY EMISSIONS ~/W AGRICULTURE WEIWIDS PROCESS SmDIES DATA SOURCES - IN~NSllY OF ENERGY AND MATERL41S USE - DY~LU~ICS OF INDUSrRLAU TECHNOLOGICAL CHANGE - REGIONAL EVOWrlON OF INDUSTRIAL METABOLISM - ENERGY AND MATERLAlS USE DATA - INDUSlRIAL PROCESS DATA - REGIONAL PRODUCrlON, CONSUMPTION, AND INDUSTRIAL PROCESS DATA 109 - FERTILIZATION - BIOMASS BURNING - IlVESrOCK DEVELOPMENT - IANDUSE CAPABILITY/ POPULATION GIS - LAND TENURE AND SeE OF HOLDINGS DATA BASE - REGIONAL CASE STUDIES FIGURE 4.1 Recommended 1990-1995 research initiatives on human sources of global change. and recommends priority research initiatives for implementation over the period from 1990 through 1995. In its deliberations on this issue the com- mittee collaborated with a wide range of scholars and institutions (see Ap- pendixes A and C), but worked particularly closely with the National Acad- emy of Engineering's Technology and the Environment Program and the Social Science Research Council's Committee for Research on Global Envi- ronmental Change. As shown in Figure 4.1, the recommended program focuses on two prin- cipal human sources of global change: industrial metabolism and land transformation. For each source, the program recommends research on integrative models, process studies, and data base development. In addi- tion, a small number of synthesis studies are proposed. Background In its 1988 report the Committee on Global Change recommended the following research initiative on human interactions with the global environ- ment (NRC, 1988~: This research initiative would focus on the relatively short-term record of the period of intensive human activities that have affected the global environ- ment. Anthropogenic changes in the earth system need to be systematically documented over the past several hundred years and analyzed as a basis for developing useful reference scenarios of future change. In particular, two aspects of human activity are especially relevant to global change: land use changes, which influence both physical (e.g., albedo, evapotranspiration, and

110 RESEARCH STRATEGIES FOR THE USGCRP mace gas flux) and biological (e.g., vegetative cover arid biodiversity) van- ables; and Me industrial metabolism mat transforms resources into emission that must be absorbed arid processed by die environment. The committee also made a recommendation related to building the sci- entific foundations for research into the human dimensions of global envi- ronmental change. It recognized that research in the human dimensions of global change was relatively underdeveloped and thus there was a need to support discipline-oriented research in this area, with "the relevant research communities encouraged to develop their own internally justified research priorities relevant to global change." This is discussed further in the section "Investigator-Initiated Research" (below). After completion of the committee's 1988 report, "the green book," the Working Group on Human Interactions with Global Change was formed, with the specific task of further defining a research agenda in the areas of land transformations and industrial metabolism. This group developed an initial list of priority research topics and planned a larger workshop to bring together active researchers and representatives of related institu- tional efforts (Appendix C). In preparation for this workshop, a background literature review was prepared, as well as several brief statements describ- ing key directions for future research (Appendix B). The workshop was attended by 28 people from a wide range of disciplinary backgrounds (Appendix A). This group was asked to define the highest-priority research areas and to identify specific research needs and opportunities that could be accomplished within the next 5 years. This chapter draws heavily on the discussions at that workshop and on written material submitted by workshop participants. Priority Recommendations From among the research initiatives discussed in this chapter, the com- mittee selects eight to receive the highest and immediate priority. To de- velop analytical frameworks through integrative models of human sources of emissions and land cover change, the committee recommends foci on . global agriculture, · global greenhouse gas emissions, and regional land cover conversion, particularly in tropical forests and wetlands. To support the model development with key studies of important processes, the committee recommends foci on fertilization in agriculture, · biomass burning, and · intensity of energy and materials use.

HUMAN SOURCES OF GLOBAL CHANGE 111 To provide critical data for model development and process studies, the committee recommends · a common information system (geographic information system) for land use, land cover, or land capability and population density and a data base for global historical energy and materials use. THE RESEARCH PROGRAM Over the next 5 years the human Interactions research program focuses on the agricultural, energy, and industrial activities that generate the crucial materials flow and land use changes that are responsible for most human- induced global change. The intent is to describe the distribution of these activities in detail appropriate for incorporation into the evolving earth sys- tem models and to understand the forces in society that drive them well enough to create alternative projections of these activities over the time frame of a century. Beyond this immediate task the research effort should provide the foundation for subsequent studies of the impacts of human- induced change and efforts to control or to adapt to such change. Three general levels of scholarship are required in this effort: data col- lection, process studies, and synthesis.) . ~. . Data collection: Data collection has both a historical and a current com- ponent. It includes data on human activities that lead to changes in the chemical flows, physical properties, and surface covers of interest, as well as data on demographic, technical, and socioeconomic variables. Process studies: Two types of studies fall under the heading "process." They are most easily distinguished by the following simple model of global environmental change. changes in changes in chemical flows, emissions or changes in physical properties, = conversions per unit x mix and level or surface cover human activity of activities The first type of process study describes the emissions and conversions per unit human activity. Currently, emission coefficients for the transfor- mation of materials and energy are better understood than those for the transformation of land. Many of the coefficients for industrial processes, such as carbon dioxide emissions for various energy technologies, are well documented. In contrast, the coefficients for land use processes, such as methane emissions from various rice cultivation techniques and animal hus- bandry, are not well understood.

112 RESEARCH STRATEGIES FOR THE USGCRP The second type of process study describes the mix and level of activi- ties (supply and demand) that transform the environment. Examples of this type of process study include studies on the determinants of the level of electricity consumption or agricultural production; studies that shed light on the interrelationships between demand for various energy technologies, or for different crops or farming practices; and models of future levels of energy or agriculture production. Synthesis: Finally, in the area of synthesis, our ultimate goal is to im- prove the capacity to describe a range of potential futures for the environ- mental components of interest. Thus we are looking here for models or analytical frameworks that allow for the development of consistent future scenarios of human activities that force global environmental change. Synthesis is required to combine the two types of process studies, and to develop approaches that integrate the changes from land use and industrial metabo lism. INDUSTRIAL METABOLISM The term "industrial metabolism" has come in recent years to signify the total pattern of energy and materials flows through an industrial sector or region. The basic goal of research in this area is to understand how chang- ing levels of human population, economic activity, technology, and social organization influence the pattern of such flows" in particular the output of pollutant chemicals relevant to global change. Integration and Synthesis The committee identifies two integrative modeling goals in the area of industrial metabolism. The first, relatively well in hand, is the creation of global models of energy use and associated pollutant emissions. Such mod- els have a long history of development in studies of the greenhouse effect. They have provided internally consistent and plausible scenarios at the de- cade-to-century scale of future carbon dioxide emissions under a range of policy and development assumptions.2 In recognition of the importance of activities other than energy use as key contributors to climatic change, the need now is to develop models that provide information on other gases of interest and thus include, in addition to energy use, industrial activity and agriculture. One such effort that is under way is a greenhouse gas model based on a general equilibrium framework. Because this model synthesizes across both land use and industrial activity, it is discussed in the section "Earth Systems Information Flow Diagram for Human Interactions" (below). The second goal is to develop models that focus on the transformation of

HUMAN SOURCES OF GLOBAL CHANGE 113 materials through industrial processes. These models would be concerned not only with greenhouse gas emissions, but also with other industrial emis- sions that contribute to global environmental change. This is a more com- plex task at a much earlier stage of development. One approach to this type of modeling is under way at the Institute for Economic Analysis at New York University. This effort builds on previous work on a world input- output model. This analysis will incorporate detailed technical process information and provide quantities and geographic distribution of pollutant emissions under various scenarios as one of its outputs. "The objective of the proposed study is to identify and evaluate concrete, consistent, eco- nomically feasible strategies for environmentally sound development, that is, to examine alternative approaches to reducing poverty over the next 50 years while also reducing global pollution" (Duchin, 19891. Process Studies and New Data Three areas of process studies were singled out as being specifically needed to support the modeling work noted above. First, in certain regions and industrial sectors the amounts of energy and material being used per unit value of production are rising, while in others they are falling. Needed is a better understanding of the human factors responsible for these pat- terns. Second, research has shown that the emergence of lead technologies such as textiles, iron and steel, chemicals, and electronics has in the past led to radical transformations in the overall character of industrial metabolism. These historical cycles of technology dominance suggest the emergence of one, perhaps two, new lead technologies over the next century, with major implications for emissions and waste streams. The factors that determine the timing of these long-term transformations need to be understood. Third, changes in industrial metabolism seem to occur as integrated regional phe- nomena, rather than on a sector-by-sector basis. Needed is a deeper under- standing of the economic, technological, and institutional processes that determine such regional integration. There is a need for data base developments related to each of the process studies noted above. Global historical data are needed on the changing intensities of energy and material use across a range of human activities. Also required are global long-term records of the changing pattern of emis- sions from major transforming technologies. Finally, it will be necessary to document integrated histories of industrial input-output characteristics for selected regions around the world. The Intensity of Energy and Materials Use Materials intensity and energy intensity are defined as the quantity of material or energy consumed per unit of value created (e.g., per unit GNP

114 RESEARCH STRATEGIES FOR THE USGCRP or per unit end-use service) or as the quantity of material or energy con- sumed per capita. Studies seeking to understand the trends in energy and materials intensities are critical to an understanding of the human forcing of global environmental change because these intensities are one of the key determinants of the environmental insult caused by economic or industrial activity. There are three previous studies of particular relevance to this research area. The first is a study of trends in materials use, which concludes that the United States is indeed experiencing a trend toward dematerialization, i.e., a reduction in the quantity of material or energy consumed per unit of value (Williams et al., 1987~. This work is based on about 100 years of data on the consumption and prices of the following materials: steel, ce- ment, paper, ammonia, chlorine, aluminum, and ethylene, as well as several low- and intermediate-volume metals. This study concludes that dematerial- ization is the result of a structural shift in the United States based on the level of income. It also concludes that dematerialization may cause the rate of growth in U.S. industrial demand for energy to become zero, or even negative. A second study based on the U.S. data documents trends in U.S. energy intensity over the past 100 years. It concludes that the availability of abundant and low-cost electricity played an important role in the decline of energy intensity (measured as energy per unit GNP) that the United States has experienced since 1920 (Schurr, 1984~. Both of these studies provide important starting points. However, there is a need to examine other countries, both in similar and in different stages of development, to further identify and understand the trends in energy and materials use. Furthermore, as emphasized by a third study, it is necessary to consider what measures of dematerialization are meaningful with regard to the environment (Herman et al., 1989~. This study suggests that demate- rialization be defined as the amount of waste generated per unit industrial product and that distinctions need to be drawn between the dematerializa- tion of production and that of consumption. It also suggests that several noneconomic factors are relevant to trends in dematerialization. To gain a better understanding of the determinants of energy and materi- als intensity, new data need to be developed, analyzed for trend, and placed within a broader framework of understanding economic development. Long- term historical surveys of energy and materials use, by country, are needed. For energy, this would include data disaggregated by end use, fuel mix, energy carrier (electricity, steam loop, or on-site combustion), and the combustion or generating technology. For materials, the task is to determine the relevant materials to include in the data base and the metrics to be used in accounting for them. Candidate materials of particular environmental concern include metals, paper, plastics, chemical commodities, and fertilizers. Accounting schemes could be based on mass, as well as some other measure of environmental

HUMAN, SOURCES OF GLOBAL CHANGE 115 insult. In the case of materials, information on both the industries or eco- nomic sectors that produce the materials and the intermediate and final consumer is needed. In addition, it is important to properly account for the import and export of materials and energy, both in their raw state, and as embodied in products. With a historical record of material and energy requirements for a num- ber of countries at different stages of economic development available, analysis to understand the causes and implications of observed trends should follow. An important focus will be on the changes in energy or materials require- ments for providing end-use services.3 This is of particular interest, as the well-being of societies is based on end-use values rather than primary in- puts. Thus if a good or service can be supplied with a lower energy or materials intensity, the environmental insult can be lowered without any reduction in well-being. In addition, end-use analysis is critical for under- standing what is technically possible and therefore for developing future scenarios of materials and energy use. In examining the causes of observed trends in materials and energy in- tensity, key factors to consider include stage of economic development, level of GNP, rate of growth of GNP, level and rate of change of economic productivity, product life cycle, and the demography of infrastructure. The relevant economic data required for this analysis, such as prices, capital and labor inputs, and productivity are generally available. After an understand- ing of the causal factors underlying historical trends in energy and materials intensity is developed, the next step will be to explore the implications this has for the future by constructing plausible scenarios of future levels of energy and material use. A final task would be exploratory in nature. On the basis of the insights gained from the above analysis, it would try to develop a theory or concep- tual framework to explain the relationship between trends in materials and energy use and economic development. Specifically, this theoretical work will describe the relationship between energy and materials intensities and stages of economic development, the relationship between changes in en- ergy and materials intensity and changes in economic productivity, and the amount of energy or materials required to support economic growth. The Dynamics of Industrial and Technological Change "The two themes of ecological and economic interdependence are strongly linked through a third theme-the development and diffusion of technol- ogy" (Brooks, 1986~. Because of this linkage, improved understanding of the factors that influence the development and diffusion of technology will significantly improve our understanding of the human forcing of global environmental change and improve our ability to develop future scenarios

116 RESEARCH STRATEGIES FOR THE USGCRP of emissions from industry. Of particular relevance is research aimed at understanding what factors influence the timing of technological change at three levels of analysis: industry, sociotechnical systems, and technological eras. At the industry level, the effort will focus on case studies of specific industries that have particularly large environmental impacts, either through high energy use (e.g., aluminum manufacturing) or through emissions from specific manufacturing processes (e.g., smelters). The industries with the largest environmental effects include electric power generation, chemical manufacturing, mining, mineral processing (including metal working), and paper manufacturing. The case studies of specific industries will include detailed information on the technologies in use, including all resources used in the production process and the waste streams created. Particular attention will be paid to technological changes that affect the environment, including materials sub- stitution, the efficiency of materials and energy use, source (waste) reduc- tion technologies, and recycling. The data will also include economic indi- cators of industry and individual firm performance. Data will be historical, documenting the changes in each industry's technological and economic characteristics over the past 150 years. Data also need to be collected on promising new technologies for each industry examined.4 At the level of sociotechnical systems, previous empirical work suggests that there are long-term regularities in the evolution, diffusion, and replace- ment of these systems (i.e., there is a characteristic time constant for substi- tution between technologies).5 The goal of this effort is to understand the reasons for this time constant, why it varies across countries, and whether it varies over time. Studies are needed both at the level of specific industries and for major sociotechnical systems such as energy or transportation systems. Factors to consider in this analysis include economic growth, factor abundance and productivity, and absolute wealth, as well as institutional and cultural factors. Of particular interest are the ways in which individuals, firms, and gov- ernments influence the timing and direction of technological change. The study would seek to identify the most influential factors in the decision- making process at each of these levels, the relative importance of each set of factors in influencing technological change, and the importance of the interactions between these groups. Finally, previous research at the level of the technological eras has shown that lead technologies such as textiles, iron and steel, chemicals, and elec- tronics characterize major eras, as do their power sources of water, steam, electricity, and gasoline. Conflicting and somewhat controversial theories exist that purport to explain the assembly and differences of these lead technologies and their associated economic impacts but little has been done

HUMAN SOURCES OF GLOBAL CHANGE 117 to examine their environmental import (Ayres, 1989~. Of particular interest for global change is that the historical cycles of technology dominance suggest the emergence of one, perhaps two, new lead technologies over the next century, with major implications for emissions and waste streams. This project would identify candidates for new lead technologies and their impli- cations for emission coefficients and energy and systems intensity. Regional EYOIUtiOn of Industrial Metabolism A proven approach for analyzing industrial metabolism is the materials balance method. This method is based on the concept of conservation of mass. It tracks the use of materials and energy "from cradle to grave." In other words, it follows them from extraction through manufacturing, con- sumption, and disposal, and then to their final environmental destination. It is a tool that allows economic data to be used in conjunction with technical information on industrial processes, the use and disposal of products by consumers, and environmental transport to describe chemical flows to the environment.6 This type of analysis was used to study the Hudson-Raritan river basin. This study reconstructed the emissions of heavy metals and other chemical wastes for the past 100 years (Ayres et al., 1988~. Two important conclusions were drawn from this analysis: (1) Major sources of environmental pollutants have been shifting from production to consump- tion processes. (2) Large numbers of materials uses are inherently dissipa- tive, spreading widely into the environment. For comparison purposes, the next study should be of a river basin in a developing country. Possible candidates include the Ganges in India and the Zambezi in Zimbabwe and Mozambique. This would allow for a pre- liminary comparison of the environmental impacts of industrialization for different stages of development and under differing development paths. It would also contribute further to an understanding of how the sources of environmental perturbations shift between production and consumption dur- ing the development process. This project would require the development of two types of data bases. The first is a data base of economic statistics on production and consumption. This data base must be sufficiently disaggre- gated, both geographically (regional rather than country level statistics) and by end use. The second is a data base of the relevant industrial processes for the region of study. LAND TRANSFORMATIONS Throughout most of history, the primary way in which humans have effected change in the global environment has been by transforming the earth's land surface. In many less industrialized regions, it remains so

118 RESEARCH STRATEGIES FOR THE USGCRP today. Land transformation, in the sense used here, includes not only ac- tivities like forest clearing that change land cover type and physical proper- ties, but also those like fertilizer use that change chemical flows. Integration and Synthesis The committee identifies two integrative modeling initiatives in the field of land transformation. The first is the creation of a global model of agri- cultural activities and their associated impacts on land use, land cover, earth surface properties, and chemical flows. Such a model would play a role in global change studies directly analogous to that already served by existing energy models that forecast carbon dioxide emissions. In particular, it would relate changes in human populations, economic activity, technology, and institutional structures to changes in the extent of agricultural lands under various cropping regimes, in irrigation practices, in fertilizer use, and in other activities directly relevant to global change studies. The model should be global in scope, with a century forecasting horizon and regional resolution. A second group of models should address transformations in two land uses that the committee has determined to be of particular rel- evance to global change studies: tropical forests and coastal wetlands. In both cases, the goal would be to provide regional forecasts of the impact of human activities on the extent of the affected land uses over decade-to- century scales. Global Agriculture Model Agriculture (including pastoralism) is the human activity most closely associated with land transformation as well as a major source of nitrogen, phosphorus, and methane. Existing models that project global agricultural activities rarely extend beyond 25 to 40 years and have been designed to answer questions of demand and trade in agricultural products or food secu- rity rather than as major sources of important emissions or spurs to land conversion.7 A new generation of models is required that can develop internally con- sistent scenarios of the expansion of agricultural production over the next century to meet the needs of a world population of 10 billion. The major goal of this new modeling effort will be to estimate the bounds of environ- mental change emanating from agricultural land use changes, including earth surface properties and chemical flows. Such a model would thus track the inputs required for the intensification of agriculture, including nitrogen and phosphorous from fertilizers, irrigation, and pesticides and herbicides as well as land transformations between agriculture and other uses. In order to accomplish this, the model must incorporate resource oppor

HUMAN SOURCES OF GLOBAL CHANGE 119 "unities and constraints (agroecological considerations) and socioeconomic trajectories (e.g., demand, technology, and institutions) for the major facets of agricultural change (e.g., land expansion and intensification). In other words, the model must adequately represent the relationship between tech- nical and institutional factors, land transformations, the global environmen- tal impact of those transformations, and the impact on the local, national, and international economies. The model must provide regional resolution representing technical, economic, and institutional factors faced by different countries, particularly the current differences in agricultural development between the developed and the developing nations. Other requirements of the model include (1) that it be sufficiently open that all parameters are subject to examination and change by the user and (2) that it be sufficiently generic to enable the user to respond to changes in the problems that will need to be addressed as perceptions of local and global agricultural production and environmental assessment change over time. Land Cover Projections for the Twenty-first Century Two types of land cover have been identified as especially important because of the degree of change that they are likely to experience and the impacts that these changes will have on global environmental systems. These are forests and wetlands. Forest conversion includes deforestation and afforestation and focuses on tropical forests. This focus is taken because of the high rates of deforesta- tion throughout the tropics and the projected negative environmental im- pacts of this phenomenon global warming, species loss, sedimentation, soil degradation and because of the complexity of forces that are giving rise to it population pressures, technological capacity to deforest or affor- est and transport resources, and international demands for tropical products. Wetland conversion involves the loss and gain of lands with standing water owing to such phenomena as drainage, wetland agriculture (e.g., field raising), irrigation, pending, and reservoirs. Wetland conversions, particu- larly rice cultivation, are important in global change because of their im- pacts on atmospheric chemistry (such as methane), biodiversity, and water availability and will be driven by the need to feed and provide water for the additional 5 billion people projected on earth by the year 2050, most of whom will be situated in the tropical realms where wet rice cultivation is climatically suitable. Understanding of the rates and trajectories of these changes will follow from matching studies on the proximate sources of change (see the section "Process Studies" below) with studies on the two land cover changes. The latter will be developed by detailing the changes for a number of selected regions or countries that account for a large share of the conversion in

120 RESEARCH STRATEGIES FOR THE USGCRP question. For example, studies of forest conversion will focus on the trans- formations in Amazonia, Borneo and the Malay Peninsula, and one or two other cases. Study of wetland conversion will focus on selected cases in South and Southeast Asia, West Africa, and perhaps Central America. With data on the rates, trajectories, and processes of change, a number of scenarios for each of the cases of forest and wetland conversion will be developed. These scenarios will involve differing assumptions about the rates and trajectories of change as they are affected by changes in the driving and mitigating forces of change (e.g., international markets, popula- tion, conservation laws, and national park protection) and by estimates of the recoverability of the environment in question. One scenario for each case will focus on surprise changes, unsuspected rates or trajectories of change, and impacts of changes on the rates. These scenarios aim (1) to develop the bounds and trajectories for the future and the consequent impacts that they will have on the global environ- mental systems through chemical emissions and through physical and bio- logical changes and (2) to demonstrate the relative importance of the driving and mitigating forces of change by varying situations (and also time-space scales), including the synergisms among them, such that the impacts of policy can be projected. Process Studies The committee identifies three land transformation processes for which deeper understanding is urgently required to promote the overall goals of global change research. The first is fertilization. Needed is a better under- standing of the human determinants of rates and character of fertilizers in major agroecosystems of the world. A second process requiring immediate attention is biomass burning. How do population density, land tenure pat- terns, economic development opportunities, and other human factors affect the frequency, character, and extent of biomass burning in major agroecosystems? Finally, better understanding is needed of livestock development. At the decadal scale, what large social forces control changes in the extent, charac- ter, and location of livestock utilization by humans? Fertilization Fertilization refers to the use of synthetic fertilizers to increase agricul- tural output, with possible expansion to include herbicides and pesticides. While this includes inputs to sustain grasslands or pastures, emphasis will be placed on the use of nitrogenous fertilizers associated with the intensifi- cation of production, particularly with the use of high yielding varieties. Currently, more nitrogen is fixed synthetically than naturally, with fertilizer

HUMAN SOURCES OF GLOBAL CHANGE 121 use growing at 3 to 4 percent per year globally.8 The increased use of syn- thetic fertilizers has direct impacts on emissions to the atmosphere, water quality, albedo, and biomass and indirect impacts on alternative land uses and methane emissions through the use of wet rice production. The in- crease in fertilization is worldwide and occurs in very different sociotechnical contexts. The driving forces for fertilization in different societies require much more detailed understanding if they are to be projected over the long term. This study will examine fertilizer use trends in their differing socio- technical contexts. Biomass Burning Fire, as reflected in biomass burning, is estimated to account for 25 to 30 percent of anthropogenic carbon dioxide emissions to the atmosphere.9 In addition, it accounts for a significant portion of the emissions of other greenhouse gases, including methane, nitrous oxides, nitrogen oxide, and carbon monoxide (U.S. EPA, 1989~. It is a critical element of landscape transformation because it is important to permanent and cyclical forest clearance, to the maintenance and regeneration of grasslands and some tree species, and as a noncommercial fuel supply. Regardless of its purpose, under all circumstances it changes the albedo of the burn zone and increases particu- lates released to the atmosphere, and in many cases it leads to a loss in biodiversity, soil quality, and water retention. The reasons for its use and the impacts that it has, of course, vary by circumstance. Broadly speaking, three types of uses can be recognized- land use expansion, land intensifica- tion, and land maintenance. These can result from market pressures, local food pressures, lack of alternative fuels, and so forth. This study will situate biomass burning within these contexts and link burning to standard- ized measures, such as number of fire hours per annum, perhaps segregated into low- and high-intensity burns. Livestock Development Since the mid-1970s, livestock populations have risen by 6 percent worldwide, but by 11 percent in Africa and 19 percent in Latin America, with a subse- quent increase in methane production and deforestation (WRI and IIED, 1988~. Thus a perhaps overlooked element of change has been the expan- sion and intensification of livestock production, particularly in the develop- ing world. These include the frontier expansion of pasture in Latin America and the intensification of livestock production within traditional systems, near urban areas for commerce, and within urban areas to meet the needs of the urban poor. The impacts on the environment are both immediate and indirect. Frontier expansion typically involves deforestation and land con

122 RESEARCH STRATEGIES FOR THE USGCRP version to crop and pasture, while intensification involves increased de- mands for food and fodder, which affects land use and quality. In either case, albedo and biodiversity changes follow. An overall increase in live- stock also increases emissions from their waste. The reasons for livestock development go beyond commercial demand and local needs; in parts of Latin America, social status is gained from livestock ownership, and in Africa, cattle ownership is an integral part of social relationships. Studies of this source of global change must differentiate between cases of expansion and cases of intensification and identify the related environmental changes and forces that give rise to livestock development. Data Needs Three data base developments are required in support of a better under- standing of land use transformation as a human source of global change. First is a capability to compare population census data, land cover data, land use data, and land capability data within a common information sys- tem. Second is the development of a global data base on land tenure and size of holdings-two variables of importance in determining patterns of land transformation. Finally, there is a need to assure that regional case study data collected in various aspects of the global change program dealing with land transformation are complementary to the maximum extent possible. The danger is an uncoordinated approach in which ecological data are col- lected at one site, tropospheric chemistry data at another, and human activ- ity data at a third. Instead, plans should be advanced for the establishment of long-term regional resource sites where relevant studies from the natural and human sciences can be conducted in concert, and their data sets pooled. Land Use, Land Cover, or Land CapabilitylPopulation Density Geographic Information System The universal measure of potential human activity is the number of per- sons within a unit area. Repeated censuses, usually on a decadal basis, take place in most countries of the world, and their accuracy exceeds that of most other global data sets (errors have been estimated at less than 3 to 20 percent). Many flows and land use changes seem directly proportional to population changes, and for others population may be the best available short-term surrogate for potential human impact. But population data are normally collected by administrative or political divisions of national terri- tory and thus do not relate directly to land use or capability. Thus the first candidate for a human interaction data set is an integrated land cover, land use, or land capability/population density geographic information system (GIS) at a resolution of 10,000 to 100,000 km2. Such work should merge

HUMAN SOURCES OF GLOBAL CHANGE 123 the different global land surface data sets with new population census re- sults as they emerge and maintain and update the resulting GIS in an appro- priate national or international institution. Once developed, this GIS should also integrate data from industrial censuses around the world that can iden- tify the geographic location of industries by four-digit standard industrial classifications. Land Tenure and Size of Holdings In order to pursue studies into the causes of various land transformations, a data base of standardized information on land tenure and land holdings is needed. Currently, the best resource for these data is the Wisconsin Land Tenure Center at the University of Wisconsin in Madison. For over two decades, this center has been collecting land tenure data for parts of Latin America, the Caribbean, Africa, and Asia. Although these data are not available in tabulated or electronic forms, original data sources are kept in their library. This proposed project would include both the continued collection of land tenure and land holding data and the development of a readily available, standardized data base, one that would be related to the GIS for land cover and population. Regional Case Studies and Research Centers The IGBP working group on data and information systems has identified a set of case studies in which efforts will be made to integrate remotely imaged and field-observed land use data. At the same time, investigator- initiated research projects on integrated case studies of global change and human impacts and response, including the Critical Environmental Zones project in the United States, have been funded in several countries. The early regional case studies should be brought together to encourage parallel or joint natural and human science studies in the same regions. These should serve as pilot efforts that lead to the development of regional re- search sites where research on long-term patterns of social, economic, and ecological change can be brought together. INTEGRATIVE STUDIES ACROSS LAND USE AND INDUSTRY Our ultimate goal is not just to understand industrial metabolism or land transformation, but rather to understand the ways in which human activities in general force changes in the earth system. Although it is too early in the overall research program to tackle this ultimate goal directly, three broad synthesis studies that could usefully be undertaken in the period from 1990

124 RESEARCH STRATEGIES FOR THE USGCRP through 1995 are recommended by the committee. These initiatives are a global model of greenhouse gas emissions, a diagram of earth system infor- mation flows for human interactions, and an analysis of the driving forces of human-induced global change. Global Model of Greenhouse Gas Emissions The first generation of global models applied to the greenhouse problem addressed a single human activity-energy use and a single greenhouse gas-carbon dioxide. The need is now clear for a second generation of models that address all the major gases and all the major human sources arising from both industrial and land use activities. Initial work has begun on such models and should be encouraged as part of the USGCRP. Desirable characteristics of the new generation of models include (1) disaggregation by country or region; (2) disaggregation by human activities leading to emissions, including energy, agriculture, manufacturing, trans- portation, and services; (3) provision of a link between the details of tech- nology (engineering or microlevel studies) and the macroeconomy; (4) modeling of interactions between the different human activities leading to emissions of greenhouse gases (e.g., the availability of biomass for energy use is dependent on agricultural technology and institutions); (5) output in 5- or 10-year steps, for 100 years; and (6) inclusion of institutional arrangements as one determinant of technological choices. A "second-generation model" of greenhouse gas emissions, which repre- sents an improvement over the current Institute of Energy Analysis/Oak Ridge Associated Universities model is being developed at Battelle Pacific Northwest Laboratories (Edmonds and Reilly, 1983; Edmonds et al., 1988~. The new model will be an improvement in the following respects: model- ing of all greenhouse gases rather than only carbon dioxide; a general equi- librium rather than partial equilibrium analytical structure; greater disaggregation of human activities, including agriculture, energy, transport, manufacture, and services; interactions between managed and unmanaged ecosystems; and improved modeling of resources, turnover in capital stocks, and inter- national trade. Another approach is the input-output analysis described in the section "Industrial Metabolism" (above). While this analysis is not aimed solely at greenhouse gas emissions, it will provide information on greenhouse gas emissions in addition to other pollutant emissions. Earth Systems Information Flow Diagram for Human Interactions The global change program has benefited tremendously from the early effort of the Earth Systems Sciences Committee (ESSC) to create a "wiring

HUMAN SOURCES OF GLOBAL CHANGE 125 diagram" of key process connections and information flows among the cli- matic, biogeochemical, and ecological components of the earth system. The ESSC effort, however, treated humans as a external boundary condition, rather than as an integral component of the system. Scholarship on the human dimensions of global change is now sufficiently advanced that the diagram should be revised to reflect our conceptual understanding of the interactions between people and environment that constitute the earth sys- tem.~° Driving Forces: Population, Economy, Technology, and Institutions Human sources of global change arise from the needs of populations and their economies and technologies and are mediated by their institutions. These driving forces of human sources are widely recognized by scientists of society and technology, who differ in emphasis and causal attribution given to each factor. Enough is already known about the historical and geographic variation in driving forces to expect that a set of quite varied clusters of driving forces will emerge related to major regional and histori- cal differences in population, economy and technology. For example, the Earth as Transformed by Human Action study of 13 key pollutant emissions and land use conversions over the past 300 years suggests three varied trajectories in which population, economy, and tech- nology each exercise successively greater influence as driving forces of these sources (Turner et al., 1990~. Regional case studies suggest that all three trajectories are at work in the world today. Thus many places can be found in the world today with carbon emissions per unit area that are simi- lar but driven by quite different combinations of forces. Further systematic study of these relations is needed. IMPLEMENTATION REQUIREMENTS Related Institutional Efforts on Human Interactions with Global Change As discussed above, the research agenda defined in this chapter is sharply focused on obtaining a better understanding of the human forcing of global environmental change. This work is complemented and supported by the work of several other organizations that are involved in developing research agendas or sponsoring research into human interactions with global envi- ronmental change. By far the largest domestic effort is being carried out in the executive branch agencies. Information on executive branch initiatives can be found in the CEES document (CES, 1989~. The activities of other

126 RESEARCH STRATEGIES FOR THE USGC8P organizations are briefly described in Appendix B. and the names of per- sons to contact for further information are included. Two organizations deserve particular mention as their agenda in part shares the focus of this committee. The Social Science Research Council has formed a Committee for Research on Global Environmental Change, which is examining six areas, one of which is land use. The National Academy of Engineering shares the interest of the Committee on Global Change in industrial metabolism as part of its Technology and the Environ- ment Program. Of Investigator-Initiated Research A strong program of investigator-initiated research is necessary to complement the highly focused nature of the research program outlined in this chapter, concentrating as it does on the human sources as inputs to the evolving model of the earth system. It is necessary that investigators be able to define studies on the impacts of global change on human activities and on societal efforts to control or to adapt to global change. As stated in Toward an Understanding of Global Change MARC, 1988), The existing research program on the human components of global change is also inadequately developed, as discussed in the background paper on the human dimension. Efforts to bring together natural, social, behavioral, and engineering scientists to examine in depth the research required on the human dimension of global change should be supported. Several research areas iden- tified in the background paper integrated methods to assess the risk and implications of long-term environmental change for resource availability at the regional scale; ways that knowledge, perceptions, and values related to global change can be more effectively brought to bear on human choices that affect global change; and evaluation and design of institutional mechanisms for better management of global change require further development in close collaboration with those relevant scientific communities in the social, behav- ioral, and engineering sciences that were not adequately represented in current . . . . planning acres. Currently, a major source of investigator-initiated research on human interactions is the National Science Foundation interdisciplinary program in human dimensions of global change. In the initial round of awards in 1989, there were 35 applications and 10 awards for $0.75 million. Funding was awarded to 4 investigator-initiated research projects as well as 6 programs for conferences, workshops, and institutionally based committees that were developing research agendas or research programs on global environmental change. These projects were of high scientific merit, diverse, and imagina- tive, spanning such topics as law and the transformation of water rights, social learning in the management of global environmental risks, critical

HUMAN SOURCES OF GLOBAL CHANGE 127 zones in global environmental change, equity issues and the global green- house effect, and the economic impacts of global environmental change. A rapid expansion of this program is envisaged over the next 5 years. Education and Training The human sciences, social and behavioral, have special requirements for education and training. Global change phenomena are not at the core of their disciplines (except for some anthropology and geography) as they are for the earth and ecological sciences, and the normal scientific program of incentives and support works poorly in mobilizing scientific effort on this vital concern. Thus special emphasis needs to be given to encouraging younger social and behavioral scientists to participate in global change re- search, to enable them to obtain training and research experience, even outside their own institutions and across disciplinary lines, if needed. A key feature for such an effort would be a predoctoral fellowship program, including cross-institutional internships, and a postdoctoral interdisciplinary program. Such a program should be institutionally based, so that it can both provide essential training and support the development of the emerging centers of human interaction research in universities, institutes, and national laboratories. Data Preparation and Dissemination It is not too early to begin to plan for data preparation and dissemination. For the data projects outlined in this study, it is important that data be systematically archived, prepared, and disseminated at a central site and made readily accessible to interested researchers. These activities might be integrated within an IGBP Regional Research Center, at one of the national laboratories, or in the emergent regional research centers described in the section "Regional Case Studies and Research Centers" (above). Oak Ridge National Laboratory has competence and experience in such archiving and dissemination through their handling of the Carbon Dioxide Information Analysis Center (CDIAC). THE STEPS BEYOND The initial research program on human interactions with global change will almost surely be overtaken by events: critical observations of ongoing global change and rapidly increasing interest in impacts and policy research. Over the S-year period of this focused research effort, it will become neces- sary to expand into these evolving research areas. The committee acknowl- edges and anticipates such expansion by emphasizing fundamental as well

128 RESEARCH STRATEGIES FOR THE USGCRP as focused research, an infrastructure for human interactions research, and close ues with the other initiatives of the behavioral and social sciences research community to understand and to respond to the challenge of global change. NOTES 1. These three levels of scholarship correspond to We scientific objectives used by FCCSET's Committee on Earth and Environmental Sciences (CEES; formerly the Committee on Earth Sciences) of documentation (observation and monitoring), improved understanding, and development of (predictive and conceptual) models. The PY 1990 initiatives for the human dimensions of global environmental change as specified by the CEES are listed below: (1) Data Base Development. This consists of two projects: (a) Land Surface Data Systems. Provide for the permanent archiving, management, access, and distribution of land surface earth science data sets for global change research on the interaction between human activities and environmental processes. (b) Improvement of Social Data Systems. Improve data resources dealing with individual and institutional actions affecting environmental changes. (2) Understanding Processes of Change. Fundamental research on the rela- tionships among global and environmental changes and human activities, including social, economic, political, legal, and institutional processes. (3) Modeling Processes of Human Interactions with the Environment. Initial methodological and substantive research to develop more sophisticated mod- els of human and institutional interactions in global change. 2. These models are generally economically based models, or are of the engi- neering-economic type. In addition, there have been some efforts to integrate the macro- and micro-levels of analysis. A thorough review of these energy models in relationship to global environmental change can be found in Toth et al. (1989~. These models are also reviewed in Appendix C of this report. The most widely used economically based model is the IEA/ORAU model (Edmonds and Reilly, 19831. A recent example of the engineering-economic type model is described in Goldemberg et al. (1988~. The most recent modeling efforts that integrate the macro- and micro- levels are described in U.S. EPA (1989~. 3. Of several studies of this type in the area of energy, the most notable recent study was done by Goldemberg et al. (1988~. 4. There exists today a family of empirically based eng~neering-economic energy and mass-balance models of conventional and advanced coal-to-electric conversion technologies. Two major efforts toward the development of process data bases were undertaken in the late 1970s and early 1980s, one at Statistics Canada and one at the International Institute for Applied Systems Analysis (IIASA). These are reviewed in Gault et al. (1985~. The current recommendation differs from these previous efforts in one important way; the interest here is in a process data base that not only describes current processes but also is both historical and forward-looking. 5. Two sources of this work are Marchetti (1983) and Marchetti and Nakicenovic (1979~. For a review of this work, see Ausubel (1989~.

HUMAN SOURCES OF GLOBAL CHANGE 129 6. ~ For a discussion of this methodology, see Ayres and Rod (1986) and Ayres et al. (1989). 7. For reviews of existing models, see Toth et al. (1989). 8. Based on data for 1974 to 1976 and 1983 to 1985 (WRI and IIED, 1988). 9. How, W.M., M.H. Liu, and P.J. Crutzen. Estimates of Annual and Regional Releases of CO2 and Other Trace Gases to the Atmosphere from Fires in the Trop- ics, Based on FAO Statistics, 1975 to 1980. Presented at Symposium on Fire Ecology at Freiberg University, Federal Republic of Germany, May 16-20, 1989. Proceedings to be published by Springer-Verlag, Berlin. 10. An initial contribution toward this goal can be found in Climate Impact As- sessment, which explores the interaction of society and climate. REFERENCES Ausubel, J.H. 1989. Regularities in technological development: An environmental view. In J.H. Ausubel and H.E. Sladovich (eds.), Technology and Environ- ment. National Academy Press, Washington D.C. Ayres, R.U. 1989. Technological Transformations and Long Waves. Research Report 89-1. International Institute for Applied Systems Analysis, Laxenburg, Austria. Ayres, R.U., and S.R. Rod. 1986. Reconstructing an environmental history: Pat- terns of pollution in the Hudson-Raritan Basin. Environment 28~4~:14-20, 39- 43. Ayres, R.U., L.W. Ayres, J.A. Tarr, and R.C. Widgery. 1988. An Historical Recon- struction of Major Pollutant Levels in the Hudson-Raritan Basin: 1880-1980. NOAA Technical Memorandum NOS OMA 42. United States Department of Commerce, National Oceanic and Atmospheric Administration, Washington, D.C. Ayres, R.U., V. Norberg-Bohm, J. Prince, W.M. Stigliani, and J.Yanowitz. 1989. Industrial Metabolism, the Environment, and Application of Materials-Bal- ance Principles for Selected Chemicals. Research Report 89-11. International Institute for Applied Systems Analysis, Laxenburg, Austria. Brooks, H. 1986. The typology of surprises in technology, institutions, and devel- opment. In W.C. Clark and R.E. Munn (eds.), Sustainable Development of the Biosphere. Cambridge University Press, New York, N.Y. Committee on Earth Sciences (CES). 1989. Our Changing Planet: The FY 1990 Research Plan. Office of Science and Technology Policy, Federal Coordinat- ing Council on Science, Engineering, and Technology, Washington, D.C. Duchin, F. 1989. Project Proposal: Strategies for Environmentally Sound Devel- opment: An Input-Output Analysis. Institute for Economic Analysis, New York University, New York. Edmonds, J.A., D.P. Barns, and W.U. Chandler. 1988. Modeling Future Green- house Gas Emissions. Pacific Northwest Laboratory, Washington, D.C. Sep- tember. Edmonds, J., and J. Reilly. 1983. Global energy and CO2 to the year 2050. The Energy Journal 4~3~.

130 RESEARCH STRATEGIES FOR TlIE USGCRP Gault, F.D., R.B. Hoffman, and B.C. McInnis. 1985. The Path to Process Data. Futures 17:509-527. Goldemberg, J., T.B. Johansson, A.K.N. Reddy, and R.H. Williams. 1988. Energy for a Sustainable World. Wiley Eastern Limited, New Delhi. Herman, R., S.A. Ardekani, and J.H. Ausubel. 1989. Dematerialization. In J.H. Ausubel and H.E. Sladovich (eds.), Technology and Environment. National Academy Press, Washington, D.C. Marchetti, C. 1983. The Automobile in a System Context: The Past 80 Years and the Next 20 Years. Research Report 83-18. International Institute for Applied Systems Analysis, Laxenburg, Austria. July. Marchetti, C., and N. Nakicenovic. 1979. The Dynamics of Energy Systems and the Logistic Substitution Model. Research Report 79-13. International Institute for Applied Systems Analysis, Laxenburg, Austria. National Aeronautics and Space Administration (NASA). 1988. Earth System Sci- ence: A Closer View. Report of the Earth Systems Sciences Committee. NASA, Washington, D.C. National Research Council (NRC). 1988. Toward an Understanding of Global Change: Initial Priorities for U.S. Contributions to the IGBP. National Academy Press, Washington, D.C. Schurr, S.H. 1984. Energy use, technological change, and productive efficiency: An economic-historical interpretation. In Annual Review of Energy 1984. Annual Reviews Press, Palo Alto, Calif. Toth, P.L., E. Hizsnyik, and W.C. Clark (eds.~. 1989. Scenarios of Socioeconomic Development for Studies of Global Environmental Change: A Critical Review. Research Report 894. International Institute for Applied Systems Analysis, Laxenburg, Austria. Turner, B., R.W. Kates, and W.C. Clark. 1990. The great transformation. 1h B. Turner, R.W. Kates, and W.C. Clark (eds.), The Eard~ as Transformed by Human Action. Cambridge University Press, New York, in press. U.S. Environmental Protection Agency (EPA). 1989. Policy Options for Stabilizing Global Climate. Draft Report to Congress. EPA, Office of Policy, Planning and Evaluation, Washington, D.C. February. Williams, R.H., E.D. Larson, and M.H. Ross. 1987. Materials, affluence, and industrial energy use. In Annual Review of Energy 1987. Annual Reviews Press, Palo Alto, Calif. World Resources ~stitute (WRI) ar~d the International Institute for Environment and Development (IIED). 1988. World Resources 1988-1989. Basic Books, New York.

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This book recommends research priorities and scientific approaches for global change research. It addresses the scientific approaches for documenting global change, developing integrated earth system models, and conducting focused studies to improve understanding of global change on topics such as earth system history and human sources of global change.

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